Re: Help me decide between fixed or variable
It's true what the others say. Variable quality has come a long way and is no longer a factor, except in theory. For example, a NF or USO. Have you seen any of the torture tests? The claim that variables are fragile is obsolete. However, in theory - a fixed of the same build quality would be even better, since as always, less parts and less moving parts is more reliable. But it's moot, since how much extra durability will one need when existing high end, tactical grade variables can be used as a hammer to drive nails or stakes? Or being dropped from heights that makes one cringe to watch. They survive, and do not lose zero.
On the low end, the fixed is still better - but you're not concerned with lower end optics.
There's the issue of optical quality. Fixed scopes, again in theory, will be brighter and clearer. Each lens reduces the amount of light transmitted through the scope and variables have more lenses. Particularly, lenses that move which makes matters worse. Which is why they are so expensive. High end scopes cost so much due to the precision tubes, threading and alignment of everything. The super precise fit - to eliminate or minimize unwanted movement which distorts the image quality, as well as the repeatability of the optic.
However, all that said - the glass on high end variable scopes is so very good, and they are made with such precision that it is tough to see the difference. It becomes moot. Can you benefit from the difference is the difference is too fine to discriminate?
You mentioned your budget of around $1,700....I would say NightForce for variable, and if you want a fixed - then the S&B PMII 10x. That thing is the creme de la crop of fixed scopes. I don't think there exists a better one. Just know that it has a fixed parallax setting of 300 meters. Which is brilliant on the part of S&B. It's excellent as it makes parallax a moot issue across the entire effective range of rifle cartridges like the .308 Winchester within the 1,000 yard realm, which also corresponds with the practicality of 10x magnification. One less thing to fiddle with. Very practical. However, the poseur with the safe-queen who never shoots past 100 yards will hate the lack of a side focus or parallax adjustment because shooting tiny groups at 100 yards will be difficult to do without a perfect stock weld and the image will not be the clearest it can be.
That is why it always ends up being a question of versatility. The variable gives you more options. Even if you leave it on maximum magnification all the time, you have the choice and thus the option. With the fixed, there is no option.
While I personally love fixed power scopes, the practical usefulness of variables trumps the fixed scope's slight advantages. In practical shooting situations, one may need to make shots at closer range, and having 10x is ridiculous inside of 200 meters at the expense of field of view which is the trade off. Field of view is important, since you can better track movers on lower power, and you have far greater situational awareness since you can see more of the downrange field through the scope.
With a 10x, you're stuck with 10x and it is difficult to use at short range, where things move faster relative to you. A NF with a 3.5 or 5.5 low end is much more useful. Especially 3.5x. Buying a fixed power, you assume that your targets will always be at extended ranges. If that holds true, the variable isn't needed. However, if that assumption proves wrong - which it often does in tactical or hunting applications, the fixed power scope will be a crippling limitation.
Better to have and not need, than need and not have.